使用媒体基础中的捕获引擎管理器从照片流中捕获静态图像

Question

非常感谢您的及时回复。我发布了用于使用TakePhoto（）方法捕获图像的示例代码。此方法返回成功。 OnCaptureEvent（）用于处理来自捕获引擎的事件及其返回的MF_CAPTURE_ENGINE_ERROR错误。

HRESULT TakePhoto()
{    
    HRESULT hr = m_pEngine->GetSink(MF_CAPTURE_ENGINE_SINK_TYPE_PHOTO, &pSink);
    if (FAILED(hr))
    {
        goto done;
    }

    hr = pSink->QueryInterface(IID_PPV_ARGS(&pPhoto));
    if (FAILED(hr))
    {
        goto done;
    }

    hr = m_pEngine->GetSource(&pSource);
    if (FAILED(hr))
    {
        goto done;
    }

    hr = pSource->GetCurrentDeviceMediaType(1, &pMediaType);        // 1 is Image stream index.I will get current image stream media type here.
    if (FAILED(hr))
    {
        goto done;
    }

    //Configure the photo format
    hr = CreatePhotoMediaType(pMediaType, &pMediaType2,GUID_ContainerFormatBmp);
    if (FAILED(hr))
    {
        goto done;
    }  

    hr = pPhoto->RemoveAllStreams();
    if (FAILED(hr))
    {
        goto done;
    }

    DWORD dwSinkStreamIndex;
    // Try to connect the first still image stream to the photo sink
    if(bHasPhotoStream)
    {
        hr = pPhoto->AddStream((DWORD)MF_CAPTURE_ENGINE_PREFERRED_SOURCE_STREAM_FOR_PHOTO,  pMediaType2, NULL, &dwSinkStreamIndex);         //Instead of MF_CAPTURE_ENGINE_PREFERRED_SOURCE_STREAM_FOR_PHOTO,i gave index as 1.i am getting error
        if(FAILED(hr))
        {           
            goto done;
        }       
    }       

    hr = pPhoto->SetOutputFileName(pszFileName);
    if (FAILED(hr))
    {
        goto done;
    }

    hr = m_pEngine->TakePhoto();
    if (FAILED(hr))
    {
        goto done;
    }
    return hr;
}

HRESULT OnCaptureEvent(WPARAM wParam, LPARAM lParam)
{
    GUID guidType;
    HRESULT hrStatus;

    IMFMediaEvent *pEvent = reinterpret_cast<IMFMediaEvent*>(wParam);

    hr = pEvent->GetExtendedType(&guidType);
    if (SUCCEEDED(hr))
    {
        if (guidType == MF_CAPTURE_ENGINE_ERROR)            //i got this error if i give dwSourceStreamIndex as '1' in Addstream api
        {
            DestroyCaptureEngine();
        }        
    }

    pEvent->Release();
    return hrStatus;
}